1. Field of the Invention
The present invention relates to a vehicle air conditioning system. More specifically, the present invention relates to a controller for a vehicle air conditioning system that operates a compressor of the vehicle air conditioning system.
2. Background Information
Vehicles typically include an air conditioning system. Such air conditioning systems typically include a compressor that is cycled on and off to compress refrigerant, a condenser that dissipates heat held in the compressed refrigerant, an expansion device that expands and lowers the pressure of the compressed refrigerant and an evaporator arranged within the vehicle to absorb heat from within a passenger compartment of the vehicle. The compressor is usually controlled with a feedback circuit that includes detection of, for example, refrigerant pressure conditions in the low pressure section of the air conditioning system or temperature conditions at or near the evaporator.
Such air conditioning systems are not always energy efficient or effective at all times. Specifically, fluctuations in operating and ambient conditions can effect operation of the air conditioning system. For example, changes in engine RPMs, changes in weather conditions and changes in vehicle speed that effect condenser operation, among other things, can affect the effectiveness of the air conditioning system.